The general objectives of our research are to: (1) Isolate and characterize a number of bone and dentin non-collagenous proteins and proteoglycans; (2) Raise antibodies against these components to be used in biosynthetic and immunolocalization studies; (3) Develop cell and organ culture systems for studying the biosynthesis and secretion of these macromolecules; (4) Design experiments to determine the biological significance of the macromolecule. Several newly discovered proteins have been isolated from rat dentin and bone. Both polyclonal and monoclonal antibodies will be raised. To determine if they are made in bone, their biosynthesis in rat osteosarcoma cells will be studied, utilizing the antibodies for identification of biosynthetic products. Immunolocalization in bone and tooth germs will be used to decide at which stage of cellular development the antigen is expressed and the relationship to formation of mineralized tissues. The biosynthesis by a rat molar tooth germ culture system will be used to verify the biosynthetic relationship to the stage of development or to mineral deposition. The studies should provide useful information concerning the formation of mineralized tissues.